Session Initiation Protocol (SIP)

SIP is used to establish and terminate mobile, VoIP, voice and video conferencing, and multimedia sessions

Session Initiation Protocol (SIP) implements RFC 3261 with full support for SIP client and server applications. Our SIP software is available with our comprehensive software library of algorithms and protocols to implement mobile, VoIP calling, voice and video conferencing, and multimedia applications. Contact us to discuss your specific SIP application requirements. Custom designs are also available.

VOCAL’s embedded libraries include a complete range of ETSI / ITU / IEEE compliant algorithms, in addition to many other standard and proprietary algorithms. Our SIP software is optimized for execution on ANSI C and leading DSP architectures (TI, ADI, AMD, ARM, MIPS, CEVA, LSI Logic ZSP, etc.). The software libraries are modular and can be executed as a single task under a variety of operating systems or standalone with its own microkernel.

Session Initiation Protocol

Session Initiation Protocol is an application-layer control protocol that can establish, modify, and terminate multimedia sessions (conferences) such as Internet telephony calls using Voice over IP (VoIP). SIP supports user applications that require the creation and management of a session, where a session is considered an exchange of data between an association of participants. The implementation of these applications is complicated by the practices of participants: users may move between endpoints, they may be addressable by multiple names, and they may communicate in several different media – sometimes simultaneously.

Session Initiation Protocol can invite participants to already existing sessions, such as multicast conferences. Numerous protocols have been authored that carry various forms of real-time multimedia session data such as voice, video, or text messages. SIP works in concert with these protocols by enabling Internet endpoints (called user agents) to discover one another and to agree on a characterization of a session they would like to share. Media can be added to (and removed from) an existing session.

Session Initiation Protocol transparently supports name mapping and redirection services for enhanced personal mobility. To locate prospective session participants, and other functions, SIP enables the creation of an infrastructure of network hosts (called proxy servers) to which user agents can send registrations, invitations to sessions, and other requests. It is an agile, general-purpose tool for creating, modifying, and terminating sessions that works independently of underlying transport protocols and without dependency on the type of session that is being established.

Session Initiation Protocol supports:

User location: determination of the end system to be used for communication

User availability: determination of the called party to engage in communications

User capabilities: determination of the media and media parameters to be used

Session setup: “ringing”, establishment of session parameters at both called and calling party